The ANZ Bank says it is still trying to find out how much money up to 500 customers may have lost in an ATM scam.
It says fraudsters attached equipment to five machines in Auckland to read information on customers' cards, in a practice known as skimming.
ANZ National Bank says scammers are constantly updating their tactics to try to keep ahead of ATM security.
ANZ managing director of retail Kerri Thompson says an investigation is underway and the bank is checking all its machines to insure no others have been targeted.
Ms Thompson says the amount of money stolen is unknown at this stage, as is the length of time the skimmers were attached to the machines.
The bank says it is reimbursing all those affected, and customers will not lose any money.
